Bodies missing from bones?
This sometimes happens when importing rigs from other software.
For the bone shapes, simply select all the bones in pose mode, go in Property Editor → Bone Tab → Viewport Display panel. Hold the ⎇ Alt key while pressing the cross icon to delete the custom object from the entire selection:

Then switch to edit mode, and open the Relations Panel. Still with every bone selected, hold the ⎇ Alt key and check the Connected option. Now all your bones having a parent is forced to stay connected with it. Which means you can't move a bone off his parent, and so the bones' heads are on their parent's tail.